November 3rd, 2010
Paricalcitol Reduces Albuminuria in Diabetic Nephropathy
Larry Husten, PHD
Selective vitamin D receptor activation with paricalcitol may help prevent progression of renal failure in patients with diabetic nephropathy who are already taking renin-angiotensin-aldosterone system (RAAS) inhibitors, according to a new study published online in the Lancet. In the VITAL study, U.S. and European investigators randomized 281 patients with type 2 diabetes and albuminuria who were already receiving RAAS inhibitors to placebo or to one of two doses of paricalcitol.
After 24 weeks, the urinary albumin-to-creatine ratio (UACR) declined by 20% and 24-hour urinary albumin excretion fell by 28% in patients receiving the higher dose of paricalcitol. No difference in adverse events across the groups was observed. The investigators concluded that paricalcitol might “be an important adjunctive treatment, providing optimum management of renal osteodystrophy, with little hypercalcaemia, and lowering residual albuminuria.”
In an accompanying editorial, Merlin Thomas and Mark Cooper call for “long-term and larger clinical trials” to test whether paricalcitol or similar drugs “can ultimately improve mortality and cardiovascular outcomes.”
We need more of such studies to come out with positive results and help in preventing Diabetic Nephropathy.
Hard end points like doubling time of serum creatinine,progression toward ESRD & requirement of renal replacement therapy have not included in primary end points. ACR is a surrogate marker for renal disease.Number of patients allocated are small. Industry sponsored study.Both internal & external validity are questionable.Study need to be conducted with adequate sample size with hard clinical end points. Over-all I am not convinced by the utility paricalcitol to treat diabetic nephropathy yet.